Shield bond strain connector for fiber optic closure

ABSTRACT

A shield bond strain connector for a cable which has strength members therein, such as a fiber optic telecommunications cable having an outer jacket surrounding the strength members and optical fibers, the connector having (i) an inner clamping element positioned against an inner surface of the cable jacket, with a first mounting bolt attached to the inner clamping element, and a prong formed along an end of the inner clamping element, (ii) an outer clamping element positioned against an outer surface of the cable jacket, having a hole therein receiving the first mounting bolt, and being forcibly urged against the cable jacket toward the inner clamping element, (iii) a clamping plate having a second mounting bolt thereon, and (iv) a shield bond extension element having first, second and third holes therein, the first hole receiving the first mounting bolt, the second hole receiving the prong, affixing the extension element to the inner and outer clamping elements, while the third hole receives the second mounting bolt, securely fastening the strength members between the clamping plate and the extension element. The first mounting bolt extends the same direction as the second mounting bolt. The extension element has a narrowed end portion which is interposed between the inner and outer clamping elements, with the first hole being formed in the narrowed end portion. A flange formed on the clamping plate provides a positive stop and a friction fit with the top edge of the shield bond extension element. Each of these elements is preferably formed of a metallic material, such as tin-plated brass. The connector extends the shield bond and provides strain relief to the strength members located within the cable jacket.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to devices used to physicallyattach cables and provide electrical continuity between groundingsheaths in the cables, and more particularly to a shield bond strainconnector designed to secure the strength members found in fiber opticcables such as those used in telecommunications.

2. Description of the Prior Art

It is frequently necessary to join the ends of two cables, such as areused in telecommunications, to lengthen the cable system, branch offadditional cables, or repair damaged cables. It is common to useenclosures to protect the joints, whether aerial, direct buried,above-ground or below ground (plant or hand hole). The enclosures aregenerally one of two types, in-line or butt-splice. In the butt splicingof fiber optic cables, several enclosure designs employ a dome shape,i.e., a closure body that is generally elongate, and has a closed endand an open end. Several such designs are depicted in U.S. Pat. Nos.4,927,227, 5,222,183, 5,249,253 and 5,278,933, and in PCT ApplicationNo. GB93/00157.

These closures use various clamps, bolts, ties, etc., to secure thecable near the open end of the closure. See U.S. Pat. Nos. 5,097,529,5,280,556 and 5,288,946, and PCT Application Nos. US93/05742, GB93/01120and GB93/01942. These elements provide strain relief against cablestresses caused by external cable movement relative to the closure. Acable that is pulled or pushed axially, twisted, or bent must nottransmit that motion to the cable sheath opening inside of the closure.The prior art designs are less suited for fiber optic cables, however,since they include metallic components have sharp edges which can damageexposed fibers and their coatings. These designs also require manyparts, increasing the cost of the closure, and sometimes require specialtools for installation. The use of so many interconnecting partsadditionally increases installation time.

Some prior art cable terminations use shield bond connectors toadditionally secure the cable jacket, and to provide electricalcontinuity across grounding sheaths, using metallic braids. Theseconnectors typically have an inner clamping member which fits inside thecable jacket, and an outer clamping member which grips the outer surfaceof the cable jacket, and a bolt or other means for forcing the twomembers together to clamp the jacket therebetween. See, e.g., U.S. Pat.Nos. 3,787,797, 4,895,525 and 5,097,529, PCT Application No. US94/04198and German Patent No. 4,231,181. These designs are inadequate to rejointhe integrity of the cable jacket for both fiber optic and copper cablessince, for example, they cannot adequately handle the strength membersfound in fiber optic cables, such as wires or aramid fibers. Indeed, itwould be very useful to have a connector that allowed for easierconversion from copper shield bond to fiber shield bond.

In several of the foregoing designs, fiber optic storage trays, such assplice trays, are supported by or attached to the strain relief memberor closure body. The storage trays usually include guide walls tomaintain the fibers with a minimum bend radius. In the aforementioned'227, '183, and '253 patents, and in U.S. Pat. Nos. 5,323,480 and5,363,466, several splice trays, stacked during storage, are hinged to acommon base, in a stair-step fashion. U.S. Pat. No. 5,071,220 and PCTApplication No. US94/04232 show in-line closures having trays hinged toa common base in this manner. In U.S. Pat. No. 5,323,478, the trays arestacked by means of hinging strips. These hinging arrangements stillallow the fibers traveling between adjacent splice trays to becomekinked when the tray is lifted, inducing microbend losses in the fiber.They also do not make the best use of space due to the stair-stepgeometry.

Fibers that are routed between trays are often protected in spiral wraptubing or cylindrical tubing to keep the fibers from being physicallydamaged and to resist bending of the fiber to less than its minimum bendradius. Cylindrical tubing and spiral wrap both take a fair amount oftime to install since, for cylindrical tubing, the fibers must bethreaded through the tubing and, for spiral wrap, the wrap must be handcoiled about the fibers, which can be very difficult if a long length offiber is present. With spiral wrap, it is also easy to pinch a fiber asit is wrapped. Prior art fiber breakout tubes further do nothing to keepribbon fiber from unduly twisting.

Several of the splice trays shown in the aforementioned patents usesplice cradles which retain a plurality of splice elements. See alsoU.S. Pat. Nos. 4,793,681, 4,840,449 and 4,854,661. The retentionfeatures can be molded directly into the tray surface, as disclosed inU.S. Pat. No. 5,074,635. Splice inserts can be removably attached to thetrays, having retention features in the form of flexible cantileverlatches for a snap fit; see U.S. Pat. Nos. 4,489,830, 4,679,896 and5,375,185. These latches do not always firmly grip the splice elements,if many elements are present in adjacent grooves, due to thedisplacement and tolerance buildup of the material forming the retentionfeature. Repeated or extended use of the splice inserts can also lead toweakening of the retention members. In light of all of these problems,and particularly those associated with closures for fiber optic cables,it would be desirable and advantageous to devise a fiber optic closurehaving appropriate components to overcome the foregoing limitations.

SUMMARY OF THE INVENTION

The present invention provides a shield bond strain connector for acable which has strength members therein, such as a fiber optictelecommunications cable having an outer jacket surrounding the strengthmembers and optical fibers, the connector generally comprising (i) aninner clamping element positioned against an inner surface of the cablejacket, having a first mounting bolt, and a prong formed along an end ofthe inner clamping element, (ii) an outer clamping element positionedagainst an outer surface of the cable jacket, having a hole thereinreceiving the first mounting bolt, and being forcibly urged against thecable jacket toward the inner clamping element, (iii) a clamping platehaving a second mounting bolt thereon, and (iv) a shield bond extensionelement having first, second and third holes therein, the first holereceiving the first mounting bolt, the second hole receiving the prong,affixing the extension element to the inner and outer clamping elements,while the third hole receives the second mounting bolt, securelyfastening the strength members between the clamping plate and theextension element. The first mounting bolt extends the same direction asthe second mounting bolt. The extension element has a narrowed endportion which is interposed between the inner and outer clampingelements, with the first hole being formed in the narrowed end portion.A flange formed on the clamping plate provides a positive stop and afriction fit with the top edge of the shield bond extension element.Each of these elements is preferably formed of a metallic material, suchas tin-plated brass. The connector extends the shield bond and providesstrain relief to the strength members located within the cable jacket.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will best be understood by reference to the accompanyingdrawings, wherein:

FIG. 1 is a perspective view of one embodiment of the fiber dome closureof the present invention, with two cables entering the closure;

FIG. 2 is a exploded view of the closure of FIG. 1;

FIG. 3 is a perspective view of one embodiment of the strain reliefmember used with the closure of FIGS. 1 and 2;

FIG. 4 is an exploded perspective view of a shield bond strain connectorof the present invention;

FIG. 5 is a perspective view of the shield bond strain connector of FIG.4 installed on a cable;

FIG. 6 is a perspective view of the closure of FIGS. 1 and 2illustrating the transition tray;

FIG. 7 is a perspective view of the end of a piece of the split fiberrouting tube used in the present invention;

FIG. 8 is a perspective view of the closure of FIGS. 1 and 2 showing twosplice trays attached to the transition tray of FIG. 6;

FIG. 9 is a perspective view similar to FIG. 8 but illustrating onesplice tray held in an intermediate access position;

FIGS. 10A-10C are perspective views of alternative splice inserts usedin accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference now to the figures, and in particular with reference toFIGS. 1 and 2, there is depicted one embodiment 10 of the closure of thepresent invention. While this closure is particularly suited for usewith fiber optic cables, many of the features described and claimedherein may be used with little or no modification in other applications,such as copper or coax. The disclosed embodiments have general use infiber-in-the-loop applications, including pedestals, cabinets, handholes, strand mount, or on poles. These applications could includeclosures for fiber drops at video nodes in hybrid fiber/coax networks,distribution closures or fiber drop closures for fiber-to-the-curb orfiber-to-the-home networks.

Closure 10 is generally comprised of an outer housing and an innerframework, the housing including an elongate, dome body 12 having afirst, closed end and a second, open end, a tubular base 14 attached tothe open end of dome body 12, a latch wire 16 for releasably securingbody 12 to base 14, and a base plate or strain relief member 18 which isobscured in FIG. 1 by a pre-stretched tube (PST) 20. This housingconstruction is similar to 3M's Reenterable Dome Closure used forsplices of copper wire, except for strain relief member 18. In thedrawings, two cables 22 and 24 are shown entering closure 10, but thenumber of cables can vary. In the disclosed embodiment, strain reliefmember 18 has six cable ports designed to receive cables of varyingdiameters, and more than one cable may be placed in a single port ifthey are small diameter.

Dome body 12, base 14 and strain relief member 18 may be formed of anydurable material, preferably a thermoplastic (injection-moldable)polymer such as polypropylene. The illustrated construction is anabove-ground closure for butt splicing. PST 20 is preferably formed ofan elastomer, such as EPDM, and is preloaded on a collapsible core, witheither or both of its ends everted outwardly, i.e., wrapped backward onitself. After the cables are secured to strain relief member 18, andbase 14 is positioned properly against member 18, PST 20 is placed aboutthese two components and its core released, causing it to collapse aboutbase 14 and strain relief member 18, and forming a tight,water-resistant seal along their interface. Ribs are provided along theouter surface of base 14 to engage PST 20. A gel end seal such as thatshown in U.S. Pat. No. 5,258,578 may also be used. Access to theinterior of closure 10 is thereafter provided by removing dome body 12from base 14 using latch 16. Latch 16, which is preferably stainlesssteel, is pivotally attached to base 14 at two pins 26 formed with thebase. Hairpin-shaped portions of latch 16 catch on corresponding pins 28formed on body 12. The location of the hairpin-shaped portions and thepositions of pins 26 and 28 are selected to cause body 12 to be forciblyurged against base 14 and form a tight seal therewith, the seal beingfurther improved by an O-ring 30 which is placed near the top of base 14in an annular groove 32 formed on the outer surface thereof. Thediameter of O-ring 30 is matched to the width of groove 32 to provide animproved seal.

With further reference to FIG. 3, the strain relief member 18 of thepresent invention uses a novel design which provides strain relief forthe cable(s) entering closure 10, and allows quick and simpleinstallation. Strain relief member 18 includes a plate 34 having severalcutouts, roughly U-shaped, forming cable ports 36, and allowing thecables to be placed in strain relief member 18 sideways, that is,without having to thread the cable through an opening. The plate hasseveral outer surfaces 38, between adjacent ports 36, which coincidewith the shape of the inner surface of base 14 such that strain reliefmember 18 may be placed partially inside base 14 and have a tight fitbetween the inner surface thereof and surfaces 38. A series of flangesor fingers 40 formed along surfaces 38 snap around the bottom edge ofbase 14 for a solid connection. Plate 34 also has a mounting fixture 42for receiving the tray, back plate, terminal block, etc., which supportsand stores the individual fibers (or wires) and associatedinterconnection devices. In the illustrated embodiment, mounting fixture42 extends generally perpendicular to plate 34 and has a slot thereinfor receiving a tang or tab on the tray. The slot may be bent, oradditional slots provided, for a more robust attachment.

A portion of the inner surface of the ports is provided with severalrows of bumps or teeth 44 which bite into the cable jacket or fittingmaterial to more securely grasp the cable. Near these teeth, along theinner surface of ports 36, there are two entry slots or openings 46which receive cable ties 48 (see FIGS. 2 and 6) for further securing thecable, and two exit slots 50 for the ties. Respective pairs of slots 46and 50 are joined by self-guiding channels formed inside the walls ofports 36. More slots can be provided for additional cable ties, or onlyone, but two is deemed optimal. This construction allows for the quickinstallation of most cables onto strain relief member 18 in three simplesteps. First, cables ties 48 are threaded into openings 46 and pusheduntil a sufficient length extends from exits 50. Secondly, the cable isprepared, if necessary, for strain relief by wrapping the area to beclamped with a suitable fitting material, such as vinyl tape. Finally,with the cable in place in a port 36, ties 48 are cinched tightly usingpliers or a cable tie gun. After all cables are so secured, strainrelief member 18 is locked into base 14 with fingers 40 snapped firmlyagainst the bottom edge of base 14. An end seal, such as those made offoam, may be used to provide resistance to water ingress.

The cable jackets may be further secured within closure 10, for example,attached directly to the support member which is mounted on fixture 42,using conventional clamping devices, including those which provideelectrical continuity across grounding sheaths. If the cable isadditionally provided with strength members (such as thick metallicwires or high-strength aramid fibers), then the modified shield bondstrain connector 52 shown in FIGS. 4 and 5 may be used to secure thesemembers. Connector 52 utilizes two conventional clamping elements 54 and56 which secure the cable jacket 58. Inner clamping element 56 has a pinor bolt 60 which passes through a hole 62 in outer clamping element 54.Both elements 54 and 56 have a plurality of tangs or teeth 64 formedthereon for gripping jacket 58. A series of tabs or prongs, including acentral prong 66, formed at the upper end of element 56 fit againstcomplementary prongs 68.

The modification of connector 52 lies in the provision of two additionalelements 70 and 72 which serve to extend the shield bond and providestrain relief for the cable strength members 74. Shield bond extension70 has three holes 76, 78 and 80 therein. Hole 76 is formed in anarrowed end portion 82 of extension element 70 and receives bolt 60when connector 52 is assembled (narrowed end portion 82 is interposedbetween inner and outer clamping elements 54 and 56). Hole 78 receivesprong 66 of clamping element 56 which, with hole 76, serves to securelyaffix extension element 70 to clamping elements 54 and 56. Hole 80 isadapted to receive another bolt 84 formed on extension clamping plate72, whereby the strength members 74 may be secured between plate 72 andextension element 70. Bolt 84, which extends the same direction as bolt60 when extension element 70 is affixed to clamping elements 54 and 56,may be directly secured to the support member (or mounting fixture)inside closure 10. A flange 86 formed on the end of clamping plate 72serves to further stabilize the connection by providing a positive stopand friction fit with the upper edge 88 of extension element 70. Thesides 90 of clamping plate 72 are also bent to form flanges whichsimilarly engage the sides of extension element 70. Clamping plate 72may have two notches therein so that the strength members can be bentback over the plate, in the notches, for additional strain relief, andadditional flanges may be provided, for example at the narrowed portionof element 70, to restrain the bent wires. Clamping plate 72 andextension element 70 are preferably formed of a metallic material suchas a copper alloy, e.g., brass, preferably with a tin plating.

Connector 52 has several advantages. First, it can handle any kind ofstrength member, e.g., wires or aramid fibers. It does not allowstrength members to bow or buckle (for example, due to thermal cycling)because they are held at short distances from the cable sheath opening.This attribute is particularly significant in fiber optic applications.Connector 52 can be attached to different types of existing shield bondconnectors, for conversion from copper shield bond to fiber shield bond.Since it terminates the strength member close to the jacket opening, itcan be easily isolated from the fiber management devices in closure 10.Finally, because it is similar to the prior art copper shield bondconnectors, the transition for technicians from copper to fiber will beeasier.

Referring again to FIG. 2, the inner framework of closure 10 may take onvarious forms, but advantageously includes a back plate or transitiontray 92 and one or more splice trays 94 each having a cover 96 and oneor more splice inserts 98 for receiving splices 100 interconnecting aplurality of optical fibers 102. The term "splice" often refers to thepermanent interconnection of two transmission lines, as opposed to a"connector" which usually connotes a device which may be attached,detached, and re-attached, repeatedly if necessary. These terms shouldnot be so construed in such a limiting sense as used herein, however,since the present invention is equally usable with both devices thatpermanently connect and devices that temporarily connect.

Although only two splice trays 94 are depicted, more could be providedin larger embodiments of closure 10. Transition tray 92 is best seen inFIG. 6, and is elongate, having an attachment fixture 104 at one end forremovable connection with mounting fixture 42 of strain relief member18. Transition tray 92 has a floor 106 with two cylinders or spools 108formed thereon for receiving coils of optical fiber slack, such asexpress fiber not used (spliced) at this location. Another curved wall110 guides a fiber breakout tube 112 to one of the splice trays 94.Spools 108 and wall 110 maintain the optical fibers at a minimum bendradius. Tabs 114 may be used to retain the fibers in the tray. If thereis sufficient room inside dome body 12, buffer tube fiber can be coiledon the plate's outer periphery and secured with cable ties. For singletubes, the tube is terminated and secured with cable ties at theentrance and loose fiber is stored inside transition tray 92. Forexpress ribbon fiber, storage in "figure-8" patterns eliminates anytwisting of the ribbons. Tray 92 is preferably deep enough to allowmultiple crossovers of ribbons. A foam block may be attached to the backside of tray 92, such as within the cylinder formed by the molding ofthe upper spool 108, to support the trays when the closure is open,i.e., dome body 12 is removed, and the trays are extending horizontally.Another piece of foam, such as a foam donut, can be placed around thefree ends of the trays or pre-positioned within the closed end of body12 to provide resistance against vibrations and external impacts.

FIG. 7 illustrates a novel split tube 116 which may be used to route thefibers from transition tray 92 to a splice tray 94, or from one splicetray to another. Like prior art articles, fiber routing tube 116 keepsthe fibers from being physically damaged, and resists bending the fiberto less than its minimum bend radius. Unlike cylindrical tubing orspiral wrap, tube 116 is particularly suited for ribbon fiber; 12 fiberribbons stack neatly in the rectangular cross-section interior, and thisshape allows little twisting of the ribbons. Additionally, it can beinstalled on the fibers much quicker than cylindrical tubing or spiralwrap, by using an interlocking, releasable seam comprised of alongitudinal spline 118 extending the full length of the seam, and acomplementary groove 120. Spline 118 is enlarged or mushroomed at itstip, and groove 120 has a region of diminished width, to provide adovetail or snap fit, but the material of tube 116 is sufficientlyelastic (such as an EPDM/polypropylene blend) to allow the walls forminggroove 120 to expand and allow spline 118 to fully enter groove 120 andseal tube 116 along its seam. Whatever tubing is used, it canadvantageously travel below the tray pivot point to allow the fibers tomove freely without catching on any hinges, and relax to their minimumstress state.

Referring now to FIGS. 8 and 9, splice trays 94 are preferably the samegeneral shape and size of transition tray 92, and have similarstructures, including arcuate walls 122 for guiding the fibers, tabs 124for retaining them, and channels 126 for constraining the fiber breakouttubes. Trays 94 are also preferably deep enough to allow multiplecrossovers of ribbons. Channels 126 may have a snap feature to securethe tubes, or be used with cable ties. Splice trays 94 also have one ormore pad areas or depressions 128 for receiving splice inserts 98. Aclip 130 may be provided on transition tray 92 to releasably secure theadjacent splice tray 94 in its storage position, and the splice trays 94may be provided with similar clips 132. Overlapping tabs 134 formed onthe sides of splice trays 94 help keep the trays neatly stacked.Transition tray 92 and splice trays 94 are preferably molded from aninjection-moldable thermoplastic polymer such as polycarbonate. Whenused with the other thermoplastic components described above (body 12,base 14 and strain relief member 18), absolutely no metal components areexposed within closure 10, which is desirable for storage of alldielectric cable, and for metallic sheath cable. Connector 52 can bewrapped with, e.g., vinyl tape so that there is no exposed metal.

The use of an injection-moldable material also allows the tray hingemechanism to be formed integrally with transition tray 92 and splicetrays 94. Specifically, pivot pins 136 and 138 are formed in the uppersurface of transition tray 92, and similar pivot pins 140 and 142 areformed in the upper surfaces of splice trays 94. These pins fit withinhubs correspondingly positioned along the lower surfaces of the splicetrays. Since these pins and hubs are formed at a common end of all ofthe trays, they can be accessed (inclined) without kinking the fibersrouted around that end. The hubs have an outer wall with an irregularshape or detent, formed to bias the tray toward a position which isinclined 60° from the storage (flat) position, as shown in FIG. 9. Thepivot pins are nested in a socket having an inner surface with the sameirregular shape as the outer wall of the hub. This feature allowshands-free access to fibers in trays below the top one(s), andintegrally molded pins allow the trays to be pivoted without kinking orbreaking fibers that enter and exit the tray. To move a splice tray 94back into alignment with the other trays, or flat against transitiontray 92, two buttons 144 are pushed and the locking mechanism releases.

Several embodiments of the novel splice inserts 98 used with the presentinvention are shown in FIGS. 10A-10C. While inserts 98 are adapted toreceive either fusion or mechanical splices, and for either discrete orribbon fibers, they are equally suited to accommodate similar opticalcomponents such as couplers, splitters and attenuators. The insert 98adepicted in FIG. 10A is designed for use with mass fusion splices, andincludes a base or pad 146 having a shape generally corresponding todepressions 128 formed in splice trays 94 which, in the preferredembodiment, is rectangular or parallelogram. Ears 148 formed at the endsof pad 146 mate with correspondingly-shaped cutouts formed in tray 94 tohelp retain insert 98a in depression 128. Other means could be providedto attach the pads to the trays, such as pressure-sensitive adhesive.Insert 98a has a plurality of fingers or arms 150a which are positionedto form a series of parallel nests or grooves for receiving individualsplice elements. Arms 150a are staggered to provide a multi-point loadon the splice elements, and are preferably constructed of an elasticmaterial such as natural and synthetic rubbers, polyurethane, EPDM (orblends thereof with polypropylene), Neoprene or nitrile. Each of arms150a has a flange or hook 152 formed thereon, with the hooks along agiven side of a splice element alternatively facing opposite directions;thus, in the depicted embodiment wherein three arms are provided on eachside of the splice element, a given element is gripped by two hooksfacing the same direction at its ends, and by a third hook facing theopposite direction at its center.

FIG. 10B illustrates an alternative splice insert 98b adapted for usewith discrete mechanical splices, such as the FIBRLOK splice 154(FIBRLOK is a trademark of 3M). Arms 150b are similar to arms 150aalthough they are thinner than arms 150a and the hooks are lesspronounced. In FIG. 10C, splice insert 98c has been adapted for use withdiscrete fusion splice elements 156, and its arms 150c are nearlytriangular in cross-section, with a lower comer missing to form the hookfeature. Two layers of discrete fusion splices can be stacked in thegrooves of insert 98c to double its capacity, to twelve elements in thedepicted embodiment.

The present invention eliminates the requirement in prior art spliceinserts of added relief areas for displaced rubber, and avoids thetolerance build-up problems associated with elimination of these reliefareas, in turn reducing the overall size of the insert, and enhancingand equalizing the retaining force on the splice elements. This isachieved by providing staggered arms which are also flexible, having ahardness in the range of 30 Shore A to 50 Shore D, preferably in therange of 60-80 Shore A, and most preferably about 70 Shore A. Theconstruction of inserts 98a-98c allow for easy insertion and removal ofthe splice element without damaging the element or the interconnectedfibers.

Although the invention has been described with reference to specificembodiments, this description is not meant to be construed in a limitingsense. Various modifications of the disclosed embodiment, as well asalternative embodiments of the invention, will become apparent topersons skilled in the art upon reference to the description of theinvention. For example, nearly all of the components can be used within-line closures as well as dome closures. It is therefore contemplatedthat such modifications can be made without departing from the spirit orscope of the present invention as defined in the appended claims.

I claim:
 1. A shield bond strain connector for use with a cable jacketconnector and a cable having strength members, the shield bond strainconnector comprising:a clamping plate having a mounting bolt attachedthereto; and a shield bond extension element having first, second andthird holes therein, said first hole positioned to receive a mountingbolt of the cable jacket connector, and said second hole positioned toreceive a prong of the cable jacket connector, such that said extensionelement is affixed to the cable jacket connector when the mounting boltthereof is engaged in said first hole and when the prong thereof isengaged in said second hole, said third hole further being positioned toreceive said mounting bolt of said clamping plate such that the strengthmembers of the cable may be securely fastened between said clampingplate and said extension element.
 2. The shield bond strain connector ofclaim 1 wherein said extension element and said clamping plate areformed of a metallic material.
 3. The shield bond strain connector ofclaim 2 wherein said metallic material is brass.
 4. The shield bondstrain connector of claim 1 wherein:the cable jacket connector includesinner and outer clamping elements, the mounting bolt thereof beingformed on the inner clamping element and sized to pass through a hole inthe outer clamping element; and said extension element is flat and isinterposed between the inner and outer clamping elements of the cablejacket connector when the mounting bolt thereof is engaged in said firsthole and when the prong thereof is engaged in said second hole.
 5. Theshield bond strain connector of claim 4 wherein said mounting bolt ofsaid clamping plate extends the same direction as the mounting bolt ofthe inner clamping element when said extension element is affixed to thecable jacket connector and said mounting bolt of said clamping plate isengaged in said third hole of said extension element.
 6. The shield bondstrain connector of claim 4 wherein said extension element has anarrowed end portion which is interposed between the inner and outerclamping elements of the cable jacket connector.
 7. The shield bondstrain connector of claim 4 further comprising flange means formed onsaid clamping plate for providing a friction fit with said shield bondextension when said mounting bolt of said clamping plate is engaged insaid third hole of said extension element.
 8. The shield bond strainconnector of claim 7 wherein said extension element has a narrowed endportion which is interposed between the inner and outer clampingelements of the cable jacket connector.
 9. The shield bond strainconnector of claim 8 wherein said mounting bolt of said clamping plateextends the same direction as the mounting bolt of the inner clampingelement when said extension element is affixed to the cable jacketconnector and said mounting bolt of said clamping plate is engaged insaid third hole of said extension element.
 10. The shield bond strainconnector of claim 1 further comprising flange means formed on saidclamping plate for providing a friction fit with said shield bondextension element when said mounting bolt of said clamping plate isengaged in said third hole of said extension element.
 11. An article forsecuring a portion of a cable jacket to a support member, the articleincluding an inner clamping element, an outer clamping element, meansfor forcibly securing the inner clamping element to the outer clampingelement with the portion of the cable jacket interposed therebetween,and means for attaching the inner and outer clamping elements to thesupport member, the inner and outer clamping elements together forming ashield bond, the improvement comprising means for extending the shieldbond and for providing strain relief to strength members located withinthe cable jacket, including:a clamping plate having a mounting boltattached thereto; and a shield bond extension element having first,second and third holes therein, said first hole positioned to receive amounting bolt attached to the inner clamping element, and said secondhole positioned to receive a prong on the inner clamping element, suchthat said extension element is affixed to the inner clamping elementwhen the mounting bolt thereof is engaged in said first hole and whenthe prong thereof is engaged in said second hole, said third holefurther being positioned to receive said mounting bolt of said clampingplate such that the strength members may be securely fastened betweensaid clamping plate and said extension element.
 12. The article of claim11 further comprising flange means formed on said clamping plate forproviding a positive stop against said shield bond extension elementwhen said mounting bolt of said clamping plate is engaged in said thirdhole of said extension element.
 13. The article of claim 12 wherein:saidmounting bolt of said clamping plate extends the same direction as themounting bolt of the inner clamping element when said extension elementis affixed to the inner clamping element and said mounting bolt of saidclamping plate is engaged in said third hole of said extension element;and said extension element has a narrowed end portion which isinterposed between the inner and outer clamping elements.
 14. Thearticle of claim 11 wherein said mounting bolt of said clamping plateextends the same direction as the mounting bolt of the inner clampingelement when said extension element is affixed to the inner clampingelement and said mounting bolt of said clamping plate is engaged in saidthird hole of said extension element.
 15. The article of claim 11wherein said extension element has a narrowed end portion which isinterposed between the inner and outer clamping elements.
 16. Anenclosed cable termination comprising:a cable having a plurality ofoptical fibers, a cable jacket surrounding said fibers, and at least onestrength member within said cable jacket; a closure having a supportmember therein; and a shield bond strain connector includingan innerclamping element positioned against an inner surface of said cablejacket, having a first mounting bolt, and having a prong formed along anend thereof, an outer clamping element positioned against an outersurface of said cable jacket, having a hole therein receiving said firstmounting bolt, and being forcibly urged against said cable jacket towardsaid inner clamping element, said first mounting bolt being secured tosaid support member, a clamping plate having a second mounting boltthereon, and a shield bond extension element having first, second andthird holes therein, said first hole receiving said first mounting bolt,said second hole receiving said prong, affixing said extension elementto said inner and outer clamping elements, and said third hole receivingsaid second mounting bolt, securely fastening the strength memberbetween said clamping plate and said extension element.
 17. The cabletermination of claim 16 further comprising flange means formed on saidclamping plate providing a positive stop against said shield bondextension element.
 18. The cable termination of claim 16 wherein saidfirst mounting bolt extends the same direction as said second mountingbolt.
 19. The cable termination of claim 16 wherein said extensionelement has a narrowed end portion which is interposed between the innerand outer clamping elements, said first hole being formed in saidnarrowed end portion.